1. Field of the Invention
The present invention relates to a laser marking apparatus for a semiconductor device manufacturing process and a method for controlling same that uses irradiated laser light to mark the package surface of a lead frame into which IC devices are molded.
2. Description of the Related Art
FIG. 16 is a perspective view showing an example of a conventional laser marking apparatus. In FIG. 16, the laser marking apparatus is provided with a supplying section 1, a conveyor section 2, a discharging section 3 and a laser irradiating section 4. A plurality of magazines 6, each of which receives a plurality of molded lead frames 5, are provided in the supplying section 1.
In the conveyor section 2, the lead frames 5 are conveyed through, a pre-processing stand-by position 2A, a processing position 2B and a post-processing stand-by position 2C. A positioning mechanism 7 for positioning the lead frames 5 at the processing position 2B is provided in the conveyor section 2. The plurality of magazines 6 into which the lead frames 5 that have been processed are received are disposed in the discharging section 3.
The operation will now be described. The lead frames 5 within the magazines 6 disposed in the supplying section 1 are transported one by one to the pre-processing stand-by position 2A of the conveyor section 2 by a supplying mechanism (not shown). Thereafter, the lead frame 5 is conveyed to the processing position 2B. Then, after the positioning has been performed by the positioning mechanism 7, the surface of a package portion (not shown) of each lead frame 5 is subjected to a laser marking process by the laser irradiating section 4. Processed lead frames 5 are conveyed to the post-processing stand-by position 2C, and are stored in the magazine 6 of the discharging section 3 by a discharging mechanism (not shown).
In the thus arranged conventional laser marking apparatus, the lead frames 5 are conveyed through the supplying section 1, the pre-processing stand-by position 2A, the processing position 2B, the post-processing stand-by position 2C and the discharging section 3. However, the conveying path is arranged in a straight line, resulting in an enlargement of the entire apparatus. In addition the supplying mechanism and the discharging mechanism are provided separately which also leads to an enlargement of the entire apparatus. Furthermore, since the laser marking process is performed after positioning the lead frame 5 that has been conveyed to the processing position 2B, the time for the lead frames 5 are stopped at the processing position 2B is increased and so a long time is required to mark the IC package surfaces of a large number of lead frames 5.